Luke Gosling, the federal Labor member for Solomon, has been charged over an alleged assault on the Northern Territory’s administrator earlier this month, NT police have said.

“The Northern Territory police force has charged the 54-year-old federal member for Solomon, Luke Gosling, in relation to an alleged assault on the administrator of the Northern Territory,” police said in a statement on Thursday.

The incident involving the administrator, David Connolly, whose position is similar to that of a state governor, is alleged to have occurred at a cultural festival in Darwin on 18 July.

Police arrested Gosling on Thursday morning. They subsequently said he had been “charged with two counts of assault on the administrator” and had been bailed to appear before Darwin local court on 1 September.

Gosling, a former military officer, is the federal special envoy for defence, veterans’ affairs and northern Australia. He was first elected to the parliament in 2016.

The prime minister, Anthony Albanese, declined to comment on Thursday’s arrest.

“There is a legal process under way. It would be inappropriate to comment further,” a spokesperson for the PM said.

Gosling had previously denied having any altercation with Connolly, and NT media reported Gosling previously called the claims “ridiculous allegations that I categorically deny”.

Gosling’s lawyer, Marty Aust, on Thursday said the charges were “completely and utterly denied and will be contested”.

“It’s particularly concerning that the police resorted to the power of arrest when they could have dealt with the matter by way of summons or notice to appear,” Aust told reporters.

A spokesperson for Connolly said they could not comment as it was a police matter.

Liberal senator James Paterson, the shadow minister for defence, called on Albanese to stand Gosling down from his envoy role.

“The allegations facing the special envoy for defence and veterans, Luke Gosling, are incredibly serious. While everyone is entitled to the presumption of innocence, an arrest for assault requires him to immediately stand down from his duties,” Paterson wrote on social media. “The PM must act today.”

The Liberal senator Jacinta Nampijinpa Price, who represents the NT, said in a statement that Gosling’s arrest was “a deeply concerning development”. She called for him to be stood down.

“It is troubling that one of our community’s elected leaders has been arrested in relation to an alleged assault on the King’s representative in the territory,” she said.

“It would be wrong to prejudge the investigation or any future proceedings. All parties must cooperate fully with police, and the investigation must be allowed to proceed without fear, favour or political interference.”